Relationships amongst cognition, speech execution and social participation in typical aging

Typical aging is accompanied by changes in cognitive and motor speech functioning, yet the relationship between these, and the extent to which they predict social participation, a lifestyle factor protective of brain health, is under-explored. This study aimed to investigate potential relationships between fluid and crystallised cognition, and the speech subsystems of respiration/phonation and articulation, as well as their combined role in social participation. Older adults (N = 87, M = 71.48, SD = 6.71) completed the NIH toolbox cognition and sensation domains, two maximum performance tasks assessing phonation (a sustained ‘a’ vowel task) and articulation (a trisyllabic syllable repetition task) and two connected speech tasks (passage reading & monologue). Participants also completed self-report measures of social participation (activity engagement & social network size) and communicative participation. Fluid and crystallised cognition predicted articulatory speed during syllable repetition but not during connected speech. Objective measures of cognition and articulation rate did not predict older adults’ social participation. However, self-reported speech difficulty, a measured covariate, was associated with less communicative participation. While everyday communication is generally well maintained, there are subtle relationships between cognition and articulation identifiable via tasks assessing maximum articulatory capacity. Self-perception of speech appears to be the best predictor of communicative participation, regardless of objective ability, showing the importance of subjective everyday functioning. These findings extend cognitive ageing and motor speech theories by showing that speech execution is a sensorimotor domain relevant to the common cause hypothesis, and that cognition in ageing is more closely associated with articulatory than laryngeal speech motor control.